This invention pertains to a fluid filter apparatus including a container having a filtered cartridge disposed therein. Fluid flows into the container through an inlet where it is forced through the filtered cartridge into a perforated tubing in a hole in the center of the cartridge and out an outlet from the container.
Typically, a filtration apparatus generally comprises a filter vessel of generally cylindrical shape containing a replacable filter cartridge for filtering contaminants from a fluid. A typical filter cartridge comprises a filter medium or media, a support member for the media, and an endcap on each end of the media. These filter vessels are generally cylindrically shaped for ease in manufacturing, and a desired objective is to have each filtered cartridge to remove as much of the solid contaminants as possible and to have as long a life as possible. Filters may be classified in two basic types:
(1) Surface Type. Surface filtration in which the bulk of the solids removed is retained on the surface of the filter media; and
(2) Depth Type. By using a low density filter media, solids are permitted to penetrate into the depth of the filter media. Obviously, larger particles are stopped near the surface, whereas smaller particles pass deeper and deeper into the media.
In both types of filtration, filtered solids will frequently compact in such manner to give much improved efficiency of filtration in that the particles tend to cake on the surface. The cake acts as a very good filter.
Since depth type cartridges generally have a relatively small surface are, any caking on the surface will result in shorter filter life. Caking on the surface improves filtration efficiency, and in turn, higher differential pressures. Most depth type filters have a relatively small outer surface. Efforts have been made in the past to find ways of increasing that surface and, in turn, increase the life of the filter. One common method for increasing the surface area is to groove the outer surface with grooves which are circumferencially around the cartridge. Other methods are to groove longitudinally in a radial direction. Other variations of grooves are used on occasion.
In some instances, the oil filter cartridge has been made from stacked disc-like filters such as shown in U.S. Pat. No. 2,495,095 and in U.S. Pat. No. 2,554,016. Other patents in this area include U.S. Pat. Nos. 1,694,939; 2,389,431; 2,501,582; 2,548,584; 2,604,994; 2,755,937 and 4,107,050.
It is an object of this invention to have an enlarged filtering area for a given amount of filtering material.
It is a further object of this invention to prevent waste of filtering material.
It is a further object of this invention to make a cartridge of simple, easily formed shapes.